Uniform computational complexity of the derivatives of C∞-functions

  • Authors:
  • Markus Bläser

  • Affiliations:
  • Institut für Theoretische Informatik, Med. Universität zu Lübeck, Wallstr. 40, 23560 Lübeck, Germany

  • Venue:
  • Theoretical Computer Science
  • Year:
  • 2002

Quantified Score

Hi-index 5.23

Visualization

Abstract

We discuss the uniform computational complexity of the derivatives of C∞-functions in the model of Ko and Friedman (Ko, Complexity Theory of Real Functions, Birkhäuser, Basel, 1991; Ko, Friedman, Theor. Comput. Sci. 20 (1982) 323-352). We construct a polynomial time computable real function g ∈ C∞ [-1,1] such that the sequence {|g(n)(0)|}n ∈ N is not bounded by any recursive function. On the other hand, we show that if f ∈ C∞ [-1,1] is polynomial time computable and the sequence of the derivatives of f is uniformly polynomially bounded, i.e., |f(n)(x)| is bounded by 2p(n) for all x ∈ [-1,1] for some polynomial p, then the sequence {f(n)}n ∈ N is uniformly polynomial time computable.